Various configurations of paintball guns and/or markers which could be used for practical applications, recreational, and shooting trainings have become popular in recent years. For example, paintball guns can be used in professional trainings for soldiers, police officers, security personals, and/or athletic participants. The success of training and/or competition may largely depend on how closely the paintball guns mimic and/or resemble the real firearms or semi-automatic hand guns.
A drawback associated with a conventional paintball gun or marker in place of a real gun is that the appearance and handling of a conventional paintball marker are different from the appearance and handling of real firearms. Since internal structure of a paintball marker is organized differently from the internal structure of firearms, operating and handling of a paintball marker are typically different from real firearms. For example, trigger pulling weight such as takeup and creep can be different between a paintball marker and a rifle.